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The Application Of The Finite Difference Time Domain Method And Its Parallelization In EM Scattering From The Rough Surface With/without Target

Posted on:2011-07-24Degree:MasterType:Thesis
Country:ChinaCandidate:H CengFull Text:PDF
GTID:2178360302991187Subject:Radio Physics
Abstract/Summary:PDF Full Text Request
In this thesis, the application of the Finite Difference Time Domain (FDTD) method and its parallelization in the EM scattering from the rough surface with/without target are systematically introduced. The EM scattering by the targets and the one-dimensional (1D) rough surface with/without target is calculated by the FDTD method with the harmonic and the transient wave incidence, respectively. The EM scattering by the complex targets and the two-dimensional (2D) rough surface with/without complex target is also calculated and analyzed with the parallel FDTD approach. The main works are as follows:Firstly, based on the principle of the FDTD method, the EM scattering by FDTD is depicted in detail, including the difference iteration formulas, the stability condition, the numerical dispersion, the absorbing boundary, the total field/scattering field (TF/SF) boundary, as well as the near-to-far field transformation boundary. The corresponding numerical examples are also presented, which show the accuracy of the FDTD algorithms.Secondly, the near-to-far field transformation method with the harmonic wave incidence is presented for the 2D and 3D case. The bistatic radar cross sections of 2D and 3D targets are calculated, and the numerical results are tested and verified. In addition, the generation of the 1D and 2D Gaussian rough surfaces is presented, and the EM scattering with the harmonic incident wave by 1D rough surface with/without target is calculated using the FDTD method. The influence of the correlation length, the root-mean-square height, the relative dielectric constant, and the electrical conductivity of the rough surface on the EM scattering is discussed, the dependency of the size of the target and its relative location on the composite scattering is also investigated.Thirdly, the sensitive study is carried out for the expression of the transient incident wave and the near-to-far field. The backscattering radar cross section of the simple 2D and 3D target is calculated with the transient wave incidence, and the numerical results are compared and verified with those presented in the reference. The EM scattering from 1D rough surface with/without target is also examined by the FDTD method with differential Gaussian pulse wave incidence. The time domain responses in different position, the EM scattering in the backward and specular directions are analyzed in detail.Finally, the parallelization and the parallel platform are introduced. Moreover, the domain decomposition, the data exchange and the synchronization of the MPI-based parallel FDTD approach are presented. Numerical results for the EM scattering by the complex target and the 2D rough surface with/without complex target calculated by the parallel FDTD algorithms show its priority to the conventional FDTD method.
Keywords/Search Tags:FDTD, EM scattering, rough surface, complex target, parallel
PDF Full Text Request
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